diff --git a/src/optimagic/optimization/internal_optimization_problem.py b/src/optimagic/optimization/internal_optimization_problem.py
index f0951df74..0c9a9fc9b 100644
--- a/src/optimagic/optimization/internal_optimization_problem.py
+++ b/src/optimagic/optimization/internal_optimization_problem.py
@@ -23,6 +23,7 @@
     Direction,
     ErrorHandling,
     EvalTask,
+    ExtraResultFields,
     PyTree,
 )
 
@@ -55,6 +56,7 @@ def __init__(
         linear_constraints: list[dict[str, Any]] | None,
         nonlinear_constraints: list[dict[str, Any]] | None,
         logger: LogStore[Any, Any] | None,
+        static_result_fields: ExtraResultFields,
         # TODO: add hess and hessp
     ):
         self._fun = fun
@@ -73,6 +75,7 @@ def __init__(
         self._nonlinear_constraints = nonlinear_constraints
         self._logger = logger
         self._step_id: int | None = None
+        self._static_result_fields = static_result_fields
 
     # ==================================================================================
     # Public methods used by optimizers
@@ -218,6 +221,14 @@ def bounds(self) -> InternalBounds:
     def logger(self) -> LogStore[Any, Any] | None:
         return self._logger
 
+    @property
+    def converter(self) -> Converter:
+        return self._converter
+
+    @property
+    def static_result_fields(self) -> ExtraResultFields:
+        return self._static_result_fields
+
     # ==================================================================================
     # Implementation of the public functions; The main difference is that the lower-
     # level implementations return a history entry instead of adding it to the history
diff --git a/src/optimagic/optimization/optimize.py b/src/optimagic/optimization/optimize.py
index 7935de635..fc1cbdeef 100644
--- a/src/optimagic/optimization/optimize.py
+++ b/src/optimagic/optimization/optimize.py
@@ -49,7 +49,6 @@
 from optimagic.optimization.optimization_logging import log_scheduled_steps_and_get_ids
 from optimagic.optimization.optimize_result import OptimizeResult
 from optimagic.optimization.process_results import (
-    ExtraResultFields,
     process_multistart_result,
     process_single_result,
 )
@@ -64,6 +63,7 @@
     Direction,
     ErrorHandling,
     ErrorHandlingLiteral,
+    ExtraResultFields,
     NonNegativeFloat,
     PyTree,
 )
@@ -543,18 +543,6 @@ def _optimize(problem: OptimizationProblem) -> OptimizeResult:
         add_soft_bounds=problem.multistart is not None,
     )
 
-    # ==================================================================================
-    # initialize the log database
-    # ==================================================================================
-    logger: LogStore[Any, Any] | None
-
-    if problem.logging:
-        logger = LogStore.from_options(problem.logging)
-        problem_data = ProblemInitialization(problem.direction, problem.params)
-        logger.problem_store.insert(problem_data)
-    else:
-        logger = None
-
     # ==================================================================================
     # Do some things that require internal parameters or bounds
     # ==================================================================================
@@ -583,12 +571,37 @@ def _optimize(problem: OptimizationProblem) -> OptimizeResult:
         numdiff_options=problem.numdiff_options,
         skip_checks=problem.skip_checks,
     )
+    # Define static information that will be added to the OptimizeResult
+    _scalar_start_criterion = cast(
+        float, first_crit_eval.internal_value(AggregationLevel.SCALAR)
+    )
+    extra_fields = ExtraResultFields(
+        start_fun=_scalar_start_criterion,
+        start_params=problem.params,
+        algorithm=problem.algorithm.algo_info.name,
+        direction=problem.direction,
+        n_free=internal_params.free_mask.sum(),
+    )
 
+    # create x and internal_bounds
     x = internal_params.values
     internal_bounds = InternalBounds(
         lower=internal_params.lower_bounds,
         upper=internal_params.upper_bounds,
     )
+
+    # ==================================================================================
+    # initialize the log database
+    # ==================================================================================
+    logger: LogStore[Any, Any] | None
+
+    if problem.logging:
+        logger = LogStore.from_options(problem.logging)
+        problem_data = ProblemInitialization(problem.direction, problem.params)
+        logger.problem_store.insert(problem_data)
+    else:
+        logger = None
+
     # ==================================================================================
     # Create a batch evaluator
     # ==================================================================================
@@ -616,6 +629,7 @@ def _optimize(problem: OptimizationProblem) -> OptimizeResult:
         linear_constraints=None,
         nonlinear_constraints=internal_nonlinear_constraints,
         logger=logger,
+        static_result_fields=extra_fields,
     )
 
     # ==================================================================================
@@ -658,19 +672,6 @@ def _optimize(problem: OptimizationProblem) -> OptimizeResult:
     # Process the result
     # ==================================================================================
 
-    _scalar_start_criterion = cast(
-        float, first_crit_eval.internal_value(AggregationLevel.SCALAR)
-    )
-    log_reader: LogReader[Any] | None
-
-    extra_fields = ExtraResultFields(
-        start_fun=_scalar_start_criterion,
-        start_params=problem.params,
-        algorithm=problem.algorithm.algo_info.name,
-        direction=problem.direction,
-        n_free=internal_params.free_mask.sum(),
-    )
-
     if problem.multistart is None:
         res = process_single_result(
             raw_res=raw_res,
@@ -686,6 +687,7 @@ def _optimize(problem: OptimizationProblem) -> OptimizeResult:
             extra_fields=extra_fields,
         )
 
+    log_reader: LogReader[Any] | None
     if logger is not None:
         assert problem.logging is not None
         log_reader = LogReader.from_options(problem.logging)
diff --git a/src/optimagic/optimization/process_results.py b/src/optimagic/optimization/process_results.py
index 0817649f5..2843c7325 100644
--- a/src/optimagic/optimization/process_results.py
+++ b/src/optimagic/optimization/process_results.py
@@ -1,4 +1,4 @@
-from dataclasses import dataclass, replace
+from dataclasses import replace
 from typing import Any
 
 import numpy as np
@@ -7,21 +7,10 @@
 from optimagic.optimization.convergence_report import get_convergence_report
 from optimagic.optimization.optimize_result import MultistartInfo, OptimizeResult
 from optimagic.parameters.conversion import Converter
-from optimagic.typing import AggregationLevel, Direction, PyTree
+from optimagic.typing import AggregationLevel, Direction, ExtraResultFields
 from optimagic.utilities import isscalar
 
 
-@dataclass(frozen=True)
-class ExtraResultFields:
-    """Fields for OptimizeResult that are not part of InternalOptimizeResult."""
-
-    start_fun: float
-    start_params: PyTree
-    algorithm: str
-    direction: Direction
-    n_free: int
-
-
 def process_single_result(
     raw_res: InternalOptimizeResult,
     converter: Converter,
@@ -79,12 +68,7 @@ def process_multistart_result(
     solver_type: AggregationLevel,
     extra_fields: ExtraResultFields,
 ) -> OptimizeResult:
-    """Process results of internal optimizers.
-
-    Args:
-        res (dict): Results dictionary of an internal optimizer or multistart optimizer.
-
-    """
+    """Process results of internal optimizers."""
     if raw_res.multistart_info is None:
         raise ValueError("Multistart info is missing.")
 
diff --git a/src/optimagic/typing.py b/src/optimagic/typing.py
index 889152f79..87385d741 100644
--- a/src/optimagic/typing.py
+++ b/src/optimagic/typing.py
@@ -156,3 +156,14 @@ class MultiStartIterationHistory(TupleLikeAccess):
     history: IterationHistory
     local_histories: list[IterationHistory] | None = None
     exploration: IterationHistory | None = None
+
+
+@dataclass(frozen=True)
+class ExtraResultFields:
+    """Fields for OptimizeResult that are not part of InternalOptimizeResult."""
+
+    start_fun: float
+    start_params: PyTree
+    algorithm: str
+    direction: Direction
+    n_free: int
diff --git a/tests/optimagic/optimization/test_internal_optimization_problem.py b/tests/optimagic/optimization/test_internal_optimization_problem.py
index a0bb24a25..4c7f1f571 100644
--- a/tests/optimagic/optimization/test_internal_optimization_problem.py
+++ b/tests/optimagic/optimization/test_internal_optimization_problem.py
@@ -18,11 +18,29 @@
     InternalOptimizationProblem,
 )
 from optimagic.parameters.conversion import Converter
-from optimagic.typing import AggregationLevel, Direction, ErrorHandling, EvalTask
+from optimagic.typing import (
+    AggregationLevel,
+    Direction,
+    ErrorHandling,
+    EvalTask,
+    ExtraResultFields,
+)
+
+
+@pytest.fixture
+def extra_fields():
+    out = ExtraResultFields(
+        start_fun=100,
+        start_params=np.arange(3),
+        algorithm="bla",
+        direction=Direction.MINIMIZE,
+        n_free=3,
+    )
+    return out
 
 
 @pytest.fixture
-def base_problem():
+def base_problem(extra_fields):
     """Set up a basic InternalOptimizationProblem that can be modified for tests."""
 
     def fun(params):
@@ -72,6 +90,7 @@ def fun_and_jac(params):
         linear_constraints=linear_constraints,
         nonlinear_constraints=nonlinear_constraints,
         logger=None,
+        static_result_fields=extra_fields,
     )
 
     return problem
@@ -413,7 +432,7 @@ def test_max_problem_exploration_fun(max_problem):
 
 
 @pytest.fixture
-def pytree_problem(base_problem):
+def pytree_problem(extra_fields):
     def fun(params):
         assert isinstance(params, dict)
         return LeastSquaresFunctionValue(value=params)
@@ -479,6 +498,7 @@ def derivative_flatten(tree, x):
         linear_constraints=linear_constraints,
         nonlinear_constraints=nonlinear_constraints,
         logger=None,
+        static_result_fields=extra_fields,
     )
 
     return problem
@@ -543,7 +563,7 @@ def test_numerical_fun_and_jac_for_pytree_problem(pytree_problem):
 
 
 @pytest.fixture
-def error_min_problem():
+def error_min_problem(extra_fields):
     """Set up a basic InternalOptimizationProblem that can be modified for tests."""
 
     def fun(params):
@@ -603,6 +623,7 @@ def fun_and_jac(params):
         linear_constraints=linear_constraints,
         nonlinear_constraints=nonlinear_constraints,
         logger=None,
+        static_result_fields=extra_fields,
     )
 
     return problem